396 TRANSACTIONS OP SECTION D. 



reproduction and growth, the characteristics of habit, instinct, and intelligence, 

 and of the very meaning of Life itself. Amid all the maze of concrete facts that 

 century after century keeps adding to our store these, and such as these, remain 

 the great mysteries of natural science — the Magnolia naturae, to borrow a great 

 word from Bacon, who in his turn had borrowed it from St. Paul. 



Not that these are the only great problems for the biologist, nor that there 

 is even but a single class of great problems in Biology. For Bacon himself 

 speaks of the magnolia natural, quoad usus humanos, the study of which has for 

 its objects ' the prolongation of life or the retardation of age, the curing of 

 diseases counted incurable, the mitigation of pain, the making of new species 

 and transplanting of one species into another,' and so on through many more. 

 Assuredly I have no need to remind you that a great feature of this generation 

 of ours has been the way in which Biology has been justified of her children, in 

 the work of those who have studied the magnolia natures, quoad usus humanos. 



But so far are biologists from being nowadays engrossed in practical questions, 

 in applied and technical Zoology, to the neglect of its more recondite problems, 

 that there never was a time when men thought more deeply or laboured with 

 greater zeal over the fundamental phenomena of living things ; never a time 

 when they reflected in a broader spirit over such questions as purposive adapta- 

 tion, the harmonious working of the fabric of the body in relation to environment, 

 and the interplay of all the creatures that people the earth ; over the problems 

 of heredity and variation; over the mysteries of sex, and the phenomena of 

 generation and reproduction, by which phenomena, as the wise woman told, or 

 reminded, Socrates, and as Harvey said again (and for that matter, as Coleridge 

 said, and Weismann, but not quite so well) — by which, as the wise old woman 

 said, we gain our glimpse of insight into eternity and immortality. These then, 

 together with the problem of the Origin of Species, are indeed magnolia natural ; 

 and I take it that inquiry into these, deep and wide research specially directed 

 to the solution of these, is characteristic of the spirit of our time, and is the 

 pass-word of the younger generation of biologists. 



Interwoven with this high aim which is manifested in the biological work 

 of recent years is another tendency. It is the desire to bring to bear upon our 

 science, in greater measure than before, the methods and results of the other 

 sciences, both those that in the hierarchy of knowledge are set above and below 

 and those that rank alongside of our own. 



Before the great problems of which I have spoken, the cleft between Zoology 

 and Botany fades away, for the same problems are common to the twin sciences. 

 When the zoologist becomes a student not of the dead but of the living, of the 

 vital processes of the cell rather than of the dry bones of the body, he becomes 

 once more a physiologist, and the gulf between these two disciplines disappears. 

 When he becomes a physiologist, he becomes, ipso facto, a student of chemistry 

 and of physics. Even mathematics has been pressed into the service of the 

 biologist, and the calculus of probabilities is not the only branch of mathematics 

 to which he may usefully appeal. 



The physiologist has long had as his distinguishing characteristic, giving 

 his craft a rank superior to the sister branch of morphology, the fact that in 

 his great field of work, and in all the routine of his experimental research, the 

 methods of the physicist and the chemist, the lessons of the anatomist, and the 

 experience of the physician are inextricably blended in one common central field 

 of investigation and thought. But it is much more recently that the morpholo- 

 gist and embryologist have made use of the method of experiment, and of the 

 aid of the physical and chemical sciences — even of the teachings of philosophy : 

 all in order to probe into properties of the living organism that men were wont 

 to take for granted, or to regard as beyond their reach, under a narrower inter- 

 pretation of the business of the biologist. Driesch and Loeb and Roux are three 

 among many men who have become eminent in this way in recent years, and 

 their work we may take as typical of methods and aims such as those of which 

 I speak. Driesch, both by careful experiment and by philosophic insight ; Loeb, 

 by his conception of the dynamics of the cell and by his marvellous demonstra- 

 tions of chemical and mechanical fertilisation; Roux, with his theory of auto- 

 determination, and by all the labours of the school of Entwickelungsmechanik 

 which he has founded, have all in various ways, and from more or less different 



